Numerical comparison processes

The relative lengths of two rows of objects systematically affected the time to make judgments of the relative number of objects. The time to decide which row contained more objects generally increased with the amount of incongruity between length and number (e.g., reaction time was long when the numerically larger row was the shorter of the two). In addition, the time to decide that the rows contained an equal number of objects increased with the disparity in length between the rows. These results suggest that length information was used in the numerical comparison process. A model that uses an internal transformation of row length is proposed to account for the results.